Product Data1" FNPT Shell (Boiler) Side, 1 1/2" PVC Slip Union Tube (Pool) SideBuilt in PVC Unions for easy installationsRemovable titanium tube bundle heat transfer surfaceIntegrated Thermostat PocketShell made of cast ironTube side operating pressure 43.5 PSIGShell side operating pressure 43.5 PSIGOperating temperature up to 120CHeat exchanger surface made of titaniumNominal heating capacities up to 240,000 btu/hr for pool applications (Up to a 26,000 gallon pool at a 1F/hr heat up rate)Eliminates the need for external bypass as the whole pool flow goes through the heat exchangerDiameter: 3.39 in., Length: 21.46 in.*Highly recommended for use in saltwater swimming pools.Covered by a Limited Lifetime Warranty against manufacturers defects.